Intra­molecular inter­actions in μ-oxido-bis­{bis­[2-(dimethyl­amino­methyl)­phen­yl]stannol}

The title compound, [Sn₂(C₉H₁₂N)₄O(OH)₂], consists of two [2-(Me₂NCH₂)C₆H₄]₂SnOH units bridged by an O atom located on a twofold rotation axis. The unique Sn atom is six-coordinated with a (C,N)₂SnO₂ octa­hedral core, as a result of the strong intra­molecular N→Sn dative coordination trans to the Sn—O bonds [N—Sn—O = 170.24 (12) and 167.83 (10)°]. Owing to the presence of inter­molecular H...phenyl contacts, the mol­ecules are arranged in a ladder-like structure.

S1. Comment

During our work on hypercoordinated organotin(IV) compounds with the [2-(Me₂NCH₂)C₆H₄]Sn fragment (Varga et al., 2001, 2005, 2006), the title compound, (I), was isolated. It contains two [2-(Me₂NCH₂)C₆H₄]₂SnOH units bridged by an O atom (Fig. 1), which lies on a twofold axis of the space group C2/c. The angle around the bridging O2 atom [Sn1—O2—Sn1(-x, y, -z + 1/2) = 137.1 (2)°] is larger than a typical bonding angle for oxygen owing to the steric constraints imposed by the organic groups bonded to the Sn atoms.

The Sn atoms are six-coordinated as the result of strong N→Sn intramolecular dative coordination. The two N→Sn distances are almost of the same magnitude (Table 1), the bond trans to the Sn1—O2 bond being slightly stronger.

Both (C,N)₂SnO₂ cores are distorted from an ideal geometry as a consequence of the small `bite' of the pendant ligand arm [C1—Sn1—N1= 70.94 (13)° and C10—Sn1—N2 = 71.41 (14)°] and the steric repulsion between the organic groups bonded to the Sn atoms.

The intramolecular N→Sn interaction induces planar chirality at the metal centre (Varga et al., 2005, 2006) and the compound crystallizes as a racemate, i.e. a mixture of S_N1R_N2S_N1ⁱR_N2ⁱ and R_N1S_N2R_N1ⁱS_N2ⁱ isomers.

Atom H1 from the hydroxy group is involved in an intramolecular H···π interaction [H···centroid = 3.11 Å; Table 2], thus explaining the orientation of the O1—H1 bond and the absence of an acceptor for an eventual hydrogen bond involving H1. The aromatic atom H3 also participates in an intermolecular H···π interaction [H—centroid = 2.88 Å; Table 2] with a phenyl ring from a neighbouring molecule. These interactions lead to the formation of a one-dimensional polymer (Fig 2), with alternating S_N1R_N2S_N1ⁱR_N2ⁱ and R_N1S_N2R_N1ⁱS_N2ⁱ isomers. In the crystal structure, the polymers run parallel to the c axis with no further inter-chain interactions (Fig. 3).

Related literature

For related literature, see: Varga et al. (2001, 2005, 2006).

S2. Experimental

The title compound was obtained by reacting [2-(Me₂NCH₂)C₆H₄]₂SnCl₂ with an excess of KOH in a dichloromethan/water (1:1) mixture. Crystals suitable for X-ray diffraction were obtained from CDCl₃.

S3. Refinement

All H atoms were placed at calculated positions using a riding model, with C—H distances of 0.93–0.97 Å and with U_iso(H) values of 1.5U_eq(C) for methyl H and 1.2U_eq(C) for aryl H atoms. The methyl groups were allowed to rotate but not to tip. The H atom bonded to O1 was found in a difference map and refined with a restrained O—H distance of 0.83 (3) Å

Computing details

Data collection: SMART (Bruker, 2000); cell refinement: SAINT-Plus (Bruker, 2000); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXTL (Bruker, 2001); program(s) used to refine structure: SHELXTL; molecular graphics: DIAMOND (Brandenburg and Putz, 2006); software used to prepare material for publication: publCIF (Westrip, 2007).

Figures

	Fig. 1. : A view of (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level and H atoms as spheres of arbitrary radii. [Symmetry code: (i) -x, y, -z + 1/2.]
	Fig. 2. : Intra- and intermolecular interactions (represented with dashed lines) in crystal structure of compound (I). Symmetry code (i) as in Table 2.
	Fig. 3. : The crystal packing of (I), viewed along the c axis.

µ-oxido-bis{bis[2-(dimethylaminomethyl)phenyl]stannol}

Crystal data

[Sn2(C9H12N)4O(OH)2]	F(000) = 1672
Mr = 824.18	Dx = 1.524 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 2504 reflections
a = 25.518 (3) Å	θ = 2.3–21.0°
b = 9.7060 (12) Å	µ = 1.43 mm^−1
c = 16.758 (2) Å	T = 297 K
β = 120.045 (2)°	Blocks, colourless
V = 3592.9 (8) Å^3	0.25 × 0.17 × 0.12 mm
Z = 4

Data collection

Bruker SMART CCD area-detector diffractometer	3662 independent reflections
Radiation source: fine-focus sealed tube	2986 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.046
phi and ω scans	θmax = 26.4°, θmin = 1.8°
Absorption correction: multi-scan (SHELXTL; Bruker, 2001)	h = −31→31
Tmin = 0.716, Tmax = 0.847	k = −12→12
14057 measured reflections	l = −20→20

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.042	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.090	H atoms treated by a mixture of independent and constrained refinement
S = 1.13	w = 1/[σ^2(Fo^2) + (0.0337P)^2 + 0.8983P] where P = (Fo^2 + 2Fc^2)/3
3662 reflections	(Δ/σ)max < 0.001
212 parameters	Δρmax = 0.73 e Å^−3
2 restraints	Δρmin = −0.48 e Å^−3

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Sn1	0.083019 (12)	0.52253 (3)	0.312103 (18)	0.04478 (12)
N1	0.09613 (15)	0.6390 (4)	0.4707 (2)	0.0527 (9)
N2	0.20002 (15)	0.4588 (4)	0.3739 (2)	0.0563 (9)
O1	0.07815 (14)	0.4062 (4)	0.2075 (2)	0.0598 (8)
O2	0.0000	0.5968 (4)	0.2500	0.0487 (9)
C1	0.08578 (18)	0.3613 (4)	0.4026 (3)	0.0493 (10)
C2	0.10120 (17)	0.3874 (5)	0.4936 (3)	0.0503 (11)
C3	0.0974 (2)	0.2798 (6)	0.5452 (3)	0.0697 (14)
H3	0.1076	0.2957	0.6060	0.084*
C4	0.0790 (2)	0.1498 (6)	0.5083 (4)	0.0790 (15)
H4	0.0771	0.0788	0.5441	0.095*
C5	0.0633 (2)	0.1264 (5)	0.4185 (4)	0.0760 (14)
H5	0.0499	0.0397	0.3926	0.091*
C6	0.0675 (2)	0.2311 (5)	0.3663 (3)	0.0610 (12)
H6	0.0579	0.2136	0.3059	0.073*
C7	0.1228 (2)	0.5262 (5)	0.5370 (3)	0.0587 (12)
H7A	0.1127	0.5383	0.5852	0.070*
H7B	0.1665	0.5302	0.5655	0.070*
C8	0.03432 (18)	0.6662 (5)	0.4532 (3)	0.0640 (13)
H8A	0.0361	0.6914	0.5099	0.096*
H8B	0.0101	0.5848	0.4287	0.096*
H8C	0.0166	0.7402	0.4097	0.096*
C9	0.1326 (2)	0.7633 (5)	0.5073 (3)	0.0718 (14)
H9A	0.1345	0.7887	0.5640	0.108*
H9B	0.1147	0.8368	0.4635	0.108*
H9C	0.1728	0.7460	0.5186	0.108*
C10	0.12811 (17)	0.7019 (4)	0.3018 (3)	0.0476 (10)
C11	0.18324 (17)	0.6899 (5)	0.3052 (3)	0.0495 (10)
C12	0.2102 (2)	0.8060 (5)	0.2928 (3)	0.0624 (13)
H12	0.2474	0.7982	0.2956	0.075*
C13	0.1827 (2)	0.9311 (6)	0.2765 (3)	0.0687 (13)
H13	0.2017	1.0082	0.2696	0.082*
C14	0.1271 (2)	0.9448 (5)	0.2703 (3)	0.0662 (13)
H14	0.1079	1.0301	0.2576	0.079*
C15	0.1003 (2)	0.8297 (5)	0.2831 (3)	0.0566 (11)
H15	0.0628	0.8383	0.2791	0.068*
C16	0.21139 (19)	0.5487 (5)	0.3156 (3)	0.0591 (12)
H16A	0.1952	0.5069	0.2552	0.071*
H16B	0.2547	0.5589	0.3416	0.071*
C17	0.2397 (2)	0.4937 (5)	0.4709 (3)	0.0692 (14)
H17A	0.2811	0.4795	0.4872	0.104*
H17B	0.2302	0.4361	0.5085	0.104*
H17C	0.2338	0.5886	0.4808	0.104*
C18	0.2081 (2)	0.3132 (5)	0.3589 (4)	0.0753 (15)
H18A	0.1827	0.2910	0.2949	0.113*
H18B	0.1972	0.2564	0.3953	0.113*
H18C	0.2496	0.2968	0.3767	0.113*
H1	0.0417 (8)	0.398 (5)	0.169 (2)	0.070 (16)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Sn1	0.03423 (17)	0.0672 (2)	0.03355 (17)	0.00162 (13)	0.01741 (13)	0.00039 (13)
N1	0.0380 (19)	0.079 (3)	0.0385 (19)	0.0038 (18)	0.0174 (17)	−0.0023 (18)
N2	0.044 (2)	0.079 (3)	0.050 (2)	0.0089 (18)	0.0265 (19)	0.0056 (19)
O1	0.050 (2)	0.092 (2)	0.0409 (17)	0.0010 (18)	0.0251 (17)	−0.0089 (16)
O2	0.030 (2)	0.070 (3)	0.039 (2)	0.000	0.0117 (17)	0.000
C1	0.040 (2)	0.067 (3)	0.044 (2)	0.011 (2)	0.023 (2)	0.005 (2)
C2	0.039 (2)	0.077 (3)	0.037 (2)	0.014 (2)	0.0196 (19)	0.009 (2)
C3	0.064 (3)	0.098 (4)	0.050 (3)	0.022 (3)	0.031 (3)	0.014 (3)
C4	0.091 (4)	0.087 (4)	0.072 (4)	0.023 (3)	0.051 (3)	0.027 (3)
C5	0.084 (4)	0.062 (3)	0.080 (4)	0.013 (3)	0.040 (3)	0.011 (3)
C6	0.061 (3)	0.070 (3)	0.058 (3)	0.011 (2)	0.034 (3)	0.001 (2)
C7	0.046 (3)	0.093 (4)	0.034 (2)	0.010 (2)	0.018 (2)	0.001 (2)
C8	0.045 (3)	0.097 (4)	0.049 (3)	0.011 (2)	0.022 (2)	−0.009 (2)
C9	0.062 (3)	0.085 (4)	0.062 (3)	−0.010 (3)	0.026 (3)	−0.015 (3)
C10	0.036 (2)	0.070 (3)	0.037 (2)	−0.005 (2)	0.0188 (19)	−0.0043 (19)
C11	0.033 (2)	0.081 (3)	0.033 (2)	−0.003 (2)	0.0153 (18)	−0.002 (2)
C12	0.045 (3)	0.099 (4)	0.050 (3)	−0.014 (3)	0.029 (2)	−0.006 (3)
C13	0.069 (3)	0.084 (4)	0.064 (3)	−0.020 (3)	0.041 (3)	−0.008 (3)
C14	0.074 (4)	0.070 (3)	0.065 (3)	−0.003 (3)	0.043 (3)	−0.001 (2)
C15	0.051 (3)	0.073 (3)	0.054 (3)	−0.002 (2)	0.031 (2)	−0.006 (2)
C16	0.041 (2)	0.094 (4)	0.045 (3)	0.006 (2)	0.024 (2)	0.002 (2)
C17	0.052 (3)	0.106 (4)	0.043 (3)	0.012 (2)	0.020 (2)	0.012 (2)
C18	0.055 (3)	0.087 (4)	0.081 (4)	0.019 (3)	0.031 (3)	0.005 (3)

Geometric parameters (Å, º)

Sn1—O1	2.036 (3)	C8—H8A	0.9600
Sn1—O2	1.9705 (15)	C8—H8B	0.9600
Sn1—N2	2.697 (3)	C8—H8C	0.9600
Sn1—N1	2.751 (3)	C9—H9A	0.9600
Sn1—C10	2.141 (4)	C9—H9B	0.9600
Sn1—C1	2.155 (4)	C9—H9C	0.9600
N1—C9	1.458 (5)	C10—C11	1.385 (5)
N1—C7	1.462 (5)	C10—C15	1.385 (6)
N1—C8	1.477 (5)	C11—C12	1.388 (6)
N2—C16	1.444 (5)	C11—C16	1.516 (6)
N2—C17	1.460 (6)	C12—C13	1.360 (6)
N2—C18	1.468 (5)	C12—H12	0.9300
O1—H1	0.83 (3)	C13—C14	1.375 (6)
C1—C6	1.378 (6)	C13—H13	0.9300
C1—C2	1.395 (5)	C14—C15	1.383 (6)
C2—C3	1.390 (6)	C14—H14	0.9300
C2—C7	1.499 (6)	C15—H15	0.9300
C3—C4	1.379 (7)	C16—H16A	0.9700
C3—H3	0.9300	C16—H16B	0.9700
C4—C5	1.370 (7)	C17—H17A	0.9600
C4—H4	0.9300	C17—H17B	0.9600
C5—C6	1.379 (6)	C17—H17C	0.9600
C5—H5	0.9300	C18—H18A	0.9600
C6—H6	0.9300	C18—H18B	0.9600
C7—H7A	0.9700	C18—H18C	0.9600
C7—H7B	0.9700
O2—Sn1—O1	99.33 (11)	N1—C8—H8A	109.5
O2—Sn1—C10	97.99 (15)	N1—C8—H8B	109.5
O1—Sn1—C10	100.66 (14)	H8A—C8—H8B	109.5
O2—Sn1—C1	106.56 (13)	N1—C8—H8C	109.5
O1—Sn1—C1	99.76 (15)	H8A—C8—H8C	109.5
C10—Sn1—C1	144.84 (15)	H8B—C8—H8C	109.5
O2—Sn1—N2	167.83 (10)	N1—C9—H9A	109.5
O1—Sn1—N2	77.42 (12)	N1—C9—H9B	109.5
C10—Sn1—N2	71.41 (14)	H9A—C9—H9B	109.5
C1—Sn1—N2	85.59 (13)	N1—C9—H9C	109.5
O2—Sn1—N1	86.47 (8)	H9A—C9—H9C	109.5
O1—Sn1—N1	170.24 (12)	H9B—C9—H9C	109.5
C10—Sn1—N1	86.17 (13)	C11—C10—C15	118.7 (4)
C1—Sn1—N1	70.94 (13)	C11—C10—Sn1	120.3 (3)
N2—Sn1—N1	98.47 (10)	C15—C10—Sn1	120.8 (3)
C9—N1—C7	110.1 (4)	C10—C11—C12	119.6 (4)
C9—N1—C7	110.1 (4)	C10—C11—C16	119.6 (4)
C9—N1—C8	109.3 (3)	C12—C11—C16	120.6 (4)
C7—N1—C8	109.2 (3)	C13—C12—C11	120.7 (4)
C16—N2—C17	110.5 (4)	C13—C12—H12	119.6
C16—N2—C18	111.9 (4)	C11—C12—H12	119.6
C17—N2—C18	109.6 (4)	C12—C13—C14	120.7 (5)
Sn1—O1—H1	106 (3)	C12—C13—H13	119.7
Sn1^i—O2—Sn1	137.1 (2)	C14—C13—H13	119.7
C6—C1—C2	119.8 (4)	C13—C14—C15	118.8 (5)
C6—C1—Sn1	118.1 (3)	C13—C14—H14	120.6
C2—C1—Sn1	122.0 (3)	C15—C14—H14	120.6
C3—C2—C1	118.3 (4)	C14—C15—C10	121.4 (4)
C3—C2—C7	119.8 (4)	C14—C15—H15	119.3
C1—C2—C7	121.9 (4)	C10—C15—H15	119.3
C4—C3—C2	121.6 (5)	N2—C16—C11	112.4 (3)
C4—C3—H3	119.2	N2—C16—H16A	109.1
C2—C3—H3	119.2	C11—C16—H16A	109.1
C5—C4—C3	119.3 (5)	N2—C16—H16B	109.1
C5—C4—H4	120.3	C11—C16—H16B	109.1
C3—C4—H4	120.3	H16A—C16—H16B	107.9
C4—C5—C6	120.2 (5)	N2—C17—H17A	109.5
C4—C5—H5	119.9	N2—C17—H17B	109.5
C6—C5—H5	119.9	H17A—C17—H17B	109.5
C1—C6—C5	120.8 (5)	N2—C17—H17C	109.5
C1—C6—H6	119.6	H17A—C17—H17C	109.5
C5—C6—H6	119.6	H17B—C17—H17C	109.5
N1—C7—C2	112.7 (3)	N2—C18—H18A	109.5
N1—C7—H7A	109.1	N2—C18—H18B	109.5
C2—C7—H7A	109.1	H18A—C18—H18B	109.5
N1—C7—H7B	109.1	N2—C18—H18C	109.5
C2—C7—H7B	109.1	H18A—C18—H18C	109.5
H7A—C7—H7B	107.8	H18B—C18—H18C	109.5
O1—Sn1—O2—Sn1^i	57.37 (10)	C1—C2—C7—N1	31.4 (5)
C10—Sn1—O2—Sn1^i	159.64 (10)	O2—Sn1—C10—C11	−156.5 (3)
C1—Sn1—O2—Sn1^i	−45.81 (12)	O1—Sn1—C10—C11	−55.4 (3)
O2—Sn1—C1—C6	85.4 (3)	C1—Sn1—C10—C11	69.2 (4)
O1—Sn1—C1—C6	−17.5 (3)	O2—Sn1—C10—C15	17.4 (3)
C10—Sn1—C1—C6	−142.3 (3)	O1—Sn1—C10—C15	118.6 (3)
O2—Sn1—C1—C2	−90.0 (3)	C1—Sn1—C10—C15	−116.9 (4)
O1—Sn1—C1—C2	167.1 (3)	C15—C10—C11—C12	2.0 (6)
C10—Sn1—C1—C2	42.3 (4)	Sn1—C10—C11—C12	176.1 (3)
C6—C1—C2—C3	−0.2 (6)	C15—C10—C11—C16	−173.7 (4)
Sn1—C1—C2—C3	175.1 (3)	Sn1—C10—C11—C16	0.4 (5)
C6—C1—C2—C7	178.5 (4)	C10—C11—C12—C13	−0.6 (6)
Sn1—C1—C2—C7	−6.2 (5)	C16—C11—C12—C13	175.1 (4)
C1—C2—C3—C4	0.0 (7)	C11—C12—C13—C14	−1.3 (7)
C7—C2—C3—C4	−178.7 (4)	C12—C13—C14—C15	1.6 (7)
C2—C3—C4—C5	−0.7 (8)	C13—C14—C15—C10	−0.1 (7)
C3—C4—C5—C6	1.6 (8)	C11—C10—C15—C14	−1.7 (6)
C2—C1—C6—C5	1.1 (6)	Sn1—C10—C15—C14	−175.7 (3)
Sn1—C1—C6—C5	−174.4 (3)	C17—N2—C16—C11	−77.3 (4)
C4—C5—C6—C1	−1.8 (7)	C18—N2—C16—C11	160.2 (4)
C9—N1—C7—C2	−160.5 (3)	C10—C11—C16—N2	−35.6 (5)
C8—N1—C7—C2	79.5 (4)	C12—C11—C16—N2	148.7 (4)
C3—C2—C7—N1	−149.9 (4)

Symmetry code: (i) −x, y, −z+1/2.